Impacts of static and dynamic disorders on intramolecular exciton transport in organic solar cells

Abstract

Because exciton transport is important in thick-film organic solar cells (OSCs), we theoretically investigated intramolecular exciton transport along polymer chains by considering two types of intramolecular disorder—static and dynamic—each of which include both diagonal and off-diagonal disorders. The results demonstrate that static diagonal disorder (SDD) has a minor impact on exciton transport, while large static off-diagonal disorder (SOD) can result in barriers that hinder, or even terminate, exciton transport to form a trapped exciton state. Moreover, both dynamic diagonal disorder (DDD) and dynamic off-diagonal disorder (DOD) are found to be favorable to exciton transport. Importantly, DOD exhibits the ability to help the trapped exciton state to overcome the binding potential barriers derived from SOD. These results provide valuable insights into developing high-efficiency thick-film OSCs.